How many RC inputs can APM 2.5 accept? 8 or 11?

I've been reading through all the parameter explanations in the wiki and I have a question about the RC inputs. On the APM 2.5 board there are 8 input channels, but there are 11 RC parameters corresponding to 11 possible RC inputs. Is it possible for APM to accept input from ch 9-11? If so where and how can you make these connections? I am using the following setup:

CH 01 Ailerons

CH 02 Elevator

CH 03 Throttle

CH 04 Rudder

CH 05 Flap

CH 06 Mission Reset (RST_MISSION)

CH 07 Panel Selection for MinimOSD

CH 08 Mode Select (6 Modes)

CH 09 I would like to use this CH to enable Geofence (FENCE_CHANNEL)

CH 10 I would like to use this CH to reset to last flight mode after Geofence takeover (RST_SWITCH_CH)

Are these additional outputs (more than inputs) intended for use with say camera gimbals, tracking a location on the ground for instance? There once was a day where I would have thought having 5 or 6 channels was more than I could use! Now I'm wondering if 14 is enough! How times change!!

Is there anything in the existing Arduplane code that would allow say a PPM input on a select channel to allow you to expand the number of channels for simple switching functions, as in my example above for CH6,9,10?